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Reference

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Publi - cations

NBSIR 83-2719-2

NAT’L INST. OF STAND & TECH

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Center ran Electrdmzcs HKD

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Techhicrl Progress Bulletin

U S DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Electronics and Electrical Engineering

COVERING SIGNALS AND SYSTEMS PROGRAM, APRIL - SEPTEMBER 1982

May 1983

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS. Emwt Ambtor. Director
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SIGNALS AND SYSTEMS PROGRAM, ISSUE FOR APRIL 1982 - SEPTEMBER 1982

Introducti on

This compilation of abstracts of papers approved for publication by the National

Bureau of Standards covers the work of three technical divisions in the NBS

Center for Electronics and Electrical Engineering for the second half of the

Federal fiscal year, April 1982 through September 1982. These divisions are the

Electrosystems Division at Gaithersburg, MD and the Electromagnetic Fields

Division and Electromagnetic Technology Division in Boulder, CO. The work of

these divisions collectively forms the Signals and Systems Metrology Program of

the Center. A compilation of abstracts covering the work of the Signals and

Systems Metrology Program for the first half of Federal fiscal year 1982 is

available as NBSIR 83-2719-1.

The work of the remaining two divisions of the Center, the Semiconductor

Materials and Processes Division and Semiconductor Devices and Circuits Division

both at Gaithersburg, comprises the Semiconductor Technology Program. Abstracts

covering this work for the entire Federal fiscal year 1982 (October 1981 through

September 1982, fifty-third through fifty-seventh quarters of the Program) have

been published in January 1983 as NBSIR 82-2636, Semiconductor Technology

Program Progress Briefs [single copies available from the Center, see back page

for address}.

New Publication Covering Entire Center

Beginning with the first quarter of Federal fiscal year 1982 (October through

December 1982), the Center is initiating publication of a single document to

cover work in both the Semiconductor Technology Program and the Signals and

Systems Metrology Program. The new publication will have the same name as the one you are now reading -- CEEE Technical Progress Bulletin — and replace the

STP Progress Briefs series. The primary purpose of the new Bui 1 eti

n

is to

p rovi de sponsors arTd other interested parties abstracts of documents approved

for publication as soon as possible. Additional information will be provided on published papers; conference and workshop proceedings; speci al -f ormat

publications, such as magnetic data tapes and videotapes; new measurement

services, including calibration services and standard reference materials; and a six-month calendar of Center events.

Publication Lists

Guides to earlier as well as recent work are the publications lists covering the

work of each division. These are revised and reissued on an approximately

annual basis and are available from the originating division [the publications

from the Semiconductor Technology Program are covered in a single list,

available from either division]. Readers are encouraged to contact any of the

individuals listed on the back page for further information.
CEEE Technical Progress Bulletin Page 1 SIGNALS AND SYSTEMS METROLOGY PROGRAM, ISSUE FOR APRIL 1982 - SEPTEMBER 1982

Mission of Signals and Systems Program: The Signals and Systems Program of the

Cent 6/ T5F ETe'CT76'hl aTTC ETKYTTC'ai Engineering provides national reference

standards, measurement methods, supporting theory and data, and traceability to the

national standards. The technical areas addressed In the Program are Identified In

the Table of Contents below.

The metrological products of the Program aid economic growth by promoting eguity and

efficiency in the marketplace, by removing metrological barriers to improved productivity and innovation, by increasing U. S. competitiveness In international markets

through facilitation of compliance with International agreements, and by providing

technical bases for the development of voluntary standards for domestic and international trade. These metrological products also aid in the development of rational

regulatory policy and promote efficient functioning of technical programs of the

Government.

TABLE OF CONTENTS

INTRODUCTION inside front cover

FAST SIGNAL ACQUISITION, PROCESSING, & TRANSMISSION

Waveform Metrology . 2

Cryoelectronic Metrology . 3

Antenna Metrology . 4

Noise Metrology ^ Microwave and Millimeter-Wave Metrology

Laser Metrology

Optical Fiber Metrology .... 7 Other Fast Signal Topics . 3

ELECTRICAL SYSTEMS

Power Systems Metrology

Pulse Power Metrology

Magnetic Materials and Measurements ...

Superconductors

ELECTROMAGNETIC INTERFERENCE . « KEY CONTACTS IN CENTER, CENTER ORGANIZATION back cover

Note: Abstracts are presented alphabetically by first author within above areas.

9

12

12

13

14

Sponsors of

Enforcement

Work Covered

standards

in this Publication National

Laboratory Department of

;

Coordination Group, DoD Electromagnetic

Force, USAF Newark Air Force Station, U.S.

R' 'arch and Development Command, USN Naval

F arch; Department of Energy, DoE Bonneville

Health and Human Services, HHS National Center .. . (formerly Bureau of Radiological Health), HHS National Institute of Occupational

S<fetv and Health- Department of Transportation. DoT National Highway Traffic Safety

Admfnisf ration; Electric Power Research Institute; and International Copper Research

Assoc i u - i on.

Bureau of Standards: NBS Law

Defense: DoD Calibratign

Compatibility Analysis Center, U.S. Air

Army, U.S. Navy, USN Naval Systems

Weapons Station, USN Office of Naval

Power Administration; Department of

for Devices and Radiological Health
Page 2 CEEE Technical Progress Bulletin

FAST SIGNAL ACQUISITION, PROCESSING, &

TRANSMISSION

Waveform metrology

Andrews, J. , Bell, B., Nahman, N. S.

,

Baldwin, E. E.; Reference Waveform

Flat Pulse Generator, Proceedings of

Conference on Precision Electric

Measurements, pp BIO- 12 (1982); also

to be published in IEEE Trans.

Instrumentation and Measurement

[approved May 1982].

The NBS Reference Flat Pulse Generator

is used to transfer dc voltage and

resistance standards to the nanosecond

domain. It provides a step amplitude of

1.000 V (open circuit) from a source impedance of 50.0 ohms. The transition

duration is 600 ps and all perturbations

are damped out to less than ±10 mV

within 5 ns. It can also be used as a time interval transfer standard.

Bell, B. A., Field, B. F., and Kibalo,

T. H. , A Fast Response Low-Frequency

Sampling Voltmeter, NBS Tech. Note

1159 (August 1982).

A low-frequency voltmeter utilizing a sampling technique implemented with

mi croprocessor-based electronics has

been developed to perform as a true rms ac voltmeter and distortion analyzer.

The instrument makes measurements accurate to ±0.1 percent (of reading) of the

fundamental frequency, total harmonic

distortion, and true rms voltage of

approximately sinusoidal inputs from 2 mV to 10 V and frequencies from 0.1 to

120 Hz. A major feature of this instrument is the special window crossing and

error function algorithms which provide

a software means for completing a mea- surement within two signal periods at

frequencies below 10 Hz.

Gans, W. L, and Nahman, N. S. , Continuous and Discrete Fourier Trans

forms of Steplike Waveforms, IEEE

Trans. on Instrumentation and

Measurement, IM-31 No. 2, p 97, June

1982.

A steplike waveform which has attained

its final value is converted into a duration-limited one which preserves the

spectrum of the original waveform and is

suitable for discrete Fourier transform

(DFT) computations. The method, which

is based upon the response of a timeinvariant linear system excited by a rectangular pulse of suitable duration,

is first applied to continuous waveforms and then to discrete (sampled)

waveforms. For completeness, the

difference (error) between the spectra

of a continuous waveform and a discrete

representation of it are reviewed.

Lentner, K.J., and Flach, D.R., An

Automatic System for AC/DC

Calibration, to be published in IEEE

Trans. Instrumentation and

Measurement.

An automatic ac/dc difference

calibration system using direct

measurement of thermocouple emfs is

described. The system operates over a frequency range from 20 Hz to 100 kHz,

covering the voltage range from 0.5 V to

1 kV. For all voltages the total

uncertainty (including the uncertainty

of the specific reference thermal

converters used) is 50 ppm at

frequencies from 20 Hz to 20 kHz,

inclusive, and 100 ppm at higher

frequencies up to 100 kHz. In addition

to ac/dc difference testing, the system

can be used to measure some important

characteristics of thermoelements, as well as to calibrate ac voltage

calibrators and precision voltmeters.

Results of intercomparisons between the

new system and the manual NBS

calibration system, using single-range,

coaxi al -type, thermal votlage converters

as transfer standards, are reported.

The results indicate that the ac/dc

differences measured are accurate to

well within the combined total

uncertainty limits of the two systems.
CEEE Technical Progress Bulletin

Waveform Metrology , cont'd.

Lentner, K.J., and Tremaine, S.G. , A

Semiautomatic AC/DC Thermal Voltage

Converter Calibration System, NBSIR

82-2576 (September 1982).

A semiautomatic ac/dc difference

calibration system is described. The

system operates over a frequency range

of 20 Hz to 100 kHz, covering the

voltage range from 0.5 V to 1 kV. For

all voltages at frequencies in the range

from 20 Hz to 20 kHz, the total

uncertainty is 50 parts per million

(ppm), and 100 ppm for voltages at

frequencies between 20 kHz and 100 kHz.

In addition to ac/dc difference testing,

the system can be readily adapted to

calibrate precision ac digital

voltmeters or ac calibrators. Results

of extensive intercomparison testing of

the new system against a manual test

system are reported, using a multirange

thermal transfer instrument as a transport standard. The results

indicate that the ac/dc differences

measured are well within the combined

total uncertainty limits of the two

systems.

Oldham, N.M., A 50 PPM AC Reference

Standard Which Spans 1 Hz to 50 ScHz,

to be published in IEEE Trans.

Instrumentation & Measurement.

A digital sinewave generator which spans

1 Hz to 50 kHz is described. The rms amplitude is characterized by an internal thermal converter and corrected

by a microcomputer to an uncertainty of

50 ppm. Amplitude is programmable from

0 to 7.07 V rms.

Schoenwetter, H.K. , High Accuracy

Settling Time Measurements, to be

published in IEEE Trans.

Instrumentation & Measurement.

hods are described for measuring the

settling times and other dynamic

characteristics of voltage and current

output D/A converters (DACs),

operational amplifiers, and precision

Page 3

voltage step generators. Circuits are described for measuring voltage-output

device settling times as short as 1 us to within a settling error of ±2 ppm,

and current-output device settling times

as short as 40 ns to within a settling

error of ±0.012%.

Souders, T.M., Flach, D.R., and Wong,

T.C., An Automatic Test set for the

Dynamic Characterization of A/D

Converters, to be published in IEEE

Trans. Instrumentation & Measurement.

An automatic test set is described for

measuring the dynamic characteristics of

A/C converters having up to 16 bits of

resolution. The test converter is

exercised with stepped input changes

typical of the conditions of actual use.

All dynamic test parameters are under

program control, making it possible to

separate and measure dynamic errors of

various sources. Typical test results

are included.

Cryoel ectronic Metrology

Brady, R.; Correction to the Formula

for the London Moment of a Rotation

Superconductor, to be published in

Jnl. Low Temp. Physics [approved

March 1982].

This paper gives full quantum-mechanical

analysis of the magnetic field (first

discussed by London) which appears spontaneously when a sample of superconductor is set into rotation. It shows

that, for slow rotation velocities and

using certain approximations, the field

B threading a cavity within a superconductor which rotates at angular velocity

1 , is given by

eB = 2(m 0 _W/c2) _1,

where -e is the charge on the electron,

m

Q

is the free electron mass, W is the

workfunction of the superconductor, and

c is the velocity of light. In the

calculation effects which are secondorder in the rotation velocity have been

ignored, and the result is only strictly

valid at the zero of temperature.
Page 4

Cryoelectronic Metrology , cont'd.

The application of this result to

experiments using practical, non-ideal

apparatus is then Illustrated for a simple geometry.

Brady, R., Zimmerman, J. E.,

Experiment on a Superconducting

(gyroscope with No Moving Parts, to be

published in J. Low Temperature

Physics [approved August 1982].

This paper describes an experimental

investigation on a new type of superconducting gyroscope which has no moving

parts. The theory of the effect by

which the gyroscope works has been verified to an accuracy of 5%, and a rotation rate of 1 radian per second could

be distinguished. Several unexpected

sources of noise were encountered, and

these are described along with suggestions for overcoming them. It appears

to be feasible to make improvements in

the sensitivity achieved in this experiment over four orders of magnitude.

Petersons, R. L. , McDonald, D. G.

;

Voltage and Current Expressions for a Two-Junction Superconducting Interferometer, to be published in J.

Applied Physics [approved July 1982].

The average voltage and circulating

current of a superconducting interferometer containing two Josephson junctions are calculated analytically in

various approximations, as functions of

bias current and applied magnetic field

or control current. The results are useful in calculations of the noise

characteristics of a dc SQUID, as well as in other applications.

Antenna Metrology

Daywitt, W. C., An Error Analysis for

the Use of Lunar Radio Flux In Broadbeam Antenna -System Measurements, to

be published in IEEE Trans. Instrumentation and Measurement [approved June

1982].

CEEE Technical Progress Bulletin

Simple, precise expressions for lunar

diameter, average brightness

temperature, flux density, and shape

factor are presented. An analysis of

the relationship between these

parameters and corresponding errors are included. For broadbeam antennas (halfpower beamwidth > 0.5°), results show

that flux density and shape factor can

be determined with errors less than 8%

and 0.4% respectively at frequencies

below 10 GHz. Extension of the analysis

to higher frequencies is indicated.

Francis, M. H. , and Yaghjian, A. D.

,

Computations of Antenna Side-Lobe Coupling In the Near Field Using Approximate Far-Fleld Data, NBSIR 82-1674

(August 1982).

Computer programs, in particular CUPLNF

and CUPLZ, are presently in existence to

calculate the coupling loss between two

antennas provided that the amplitude and

phase of the far field are available.

However, for many antennas the complex

far field is not known accurately. In such cases it is nevertheless possible

to specify approximate far fields from a knowledge of the side-lobe level of each

antenna along the axis of separation,

and the electrical size of each antenna.

To determine the effectiveness of using

approximate side-lobe level data instead

of the detailed far fields we chose as our test antennas two hypothetical, linearly polarized, uniformly illuminated

circular antennas for which the exact

far fields are supplied to the program

CUPLNF to compute the exact near-field

coupling loss. Approximate fields are supplied to a new program ENVLP developed for the purpose of computing the

approximate near-field coupling loss.

The comparison of the results from ENVLP

to those of CUPLNF indicates that the use of approximate far fields gives an estimate of the coupling loss which is

good to about ± 5 dB. In addition, the

plane-wave transmission formula for

coupling between two antennas is used to

estimate upper-bound values of coupling

loss, comparing these upper bounds with

the maximum coupling losses obtained
CEEE Technical Progress Bulletin

Antenna Metrology, cont'd.

Page 5

from programs CUPLNF and ENVLP.

Kanda, M. , The Effects of Resistive

Loading on TEM Horns, IEEE Trans.

Electromagnetic Compatibility, EMC-24,

No. 2, pp. 245-255 (May 1982).

A short transverse electromagnetic (TEM)

horn with continuously tapered resistive

loading was developed for directional

reception or transmission of picosecond

pulses with minimal distortion. It was found to be broadband and nondi spersi ve with a low VSWR. The receiving transient response of the resistively loaded

"TEM" horn indicates that the waveform

of a 70-ps impulse is well preserved.

The theoretical analyses using the method of moments and the fast Fourier

transform (FFT) technique were performed

and agreed well with time-domain

measurements.

Kanda, M. , Chang, 0. C., and Greenlee,

D. H. , The Characteristics of Irisfed Ml 1 1 1 met er-Wave Rectangular

Microstrip Patch Antennas, Proc. 1982

IEEE Antennas and Propagation

Symposium, University of Albuquerque,

Albuquerque, New Mexico, May 24-28,

1982, pp. 292-295.

This paper describes the characteristics

of iris-fed millimeter-wave rectangular

microstrip patch antennas. A theoretical model is given to describe the

iris-fed patch antenna based on aperture

coupling to cavities. The impedance and

antenna power patterns are given.

Kanda, M. , and Ries, F. X., Time

Domain Sensors for Radiated Impulsive

Measurements, to be published in IEEE

Trans. Antennas and Propagation

[see also same title in Proc. IEEE

Int. Symposium on Electromagnetic

Compatibility, Santa Clara, California,

September 8-10, 1982, pp. 296-301].

The purpose of this paper is to review

various sensors and radiators commonly

used for time domain antenna measurements. The sensors and radiators discussed here are passive and analog

devices which convert the electromagnetic quantity of interest to a voltage

or current at their terminal ports.

Moreover, they are primary standards in

the sense that their transfer functions

can be calculated from their geometries

and are preferably flat (constant)

across a wide frequency range. One of

the major requirements for these sensors

and radiators is that the electromagnetic far fields, transmitted or received, are replicas or high-fidelity

derivatives of the original pulse.

(Note that the transmitting transfer

function of an antenna is the time

derivative of the receiving transfer

function of the same antenna which

follows from the reciprocity theorem).

For electric field strength

measurements, linear antennas loaded

nonuniformly and continuously with

resistance, or both resistance and

capacitance are discussed. Also a conical antenna and an asymptotic conical

antenna are discussed from the standpoint of an improved figure of merit.

For an improved directivity, various

types of TEM horns are discussed, e.g.,

a conducting TEM horn, a CALSPAN antenna, and a resistively loaded TEM horn.

Ma , M. T. , Arrays of Discrete

Elements, Chapter 3 in book. Antenna

Engineering Handbook, to be published

in 1983.

Invited contribution for text to be

published by McGraw-Hill Book Company.

Repjar, A. G. , and Kremer, D. P. , Accurate Evaluation of a Millimeter

Wave Compact Range Using Planar Nearfield Scanning, IEEE Trans. Antennas

and Propagation AP-30, No. 3, pp. 419-

425 (May 1982).

Significant progress in recent years has

been made on planar near-field measurements for antenna calibrations. Such

measurements are also useful in the

alignment and evaluation of compact

ranges because they provide more
Page 6 CEEE Technical Progress Bulletin

Antenna Metrology , cont'd.

Information than a limited number of

analogue plots In one dimension.

Contour plots of amplitude and phase

data obtained from more complete 2-

dlmensional measurements precisely and

accurately locate sources of problems In

the range reflector, with phase contour

plots being more useful as diagnostic

tools.

Repjar, A. G. , Newell, A. C., and Baird,

R. C., Antenna Gain Measurements by

an Extended Version of the NBS

Extrapolation Method, Digest, 1982

Conf. on Precision Electromagnetic

Measurements, Boulder, Colorado, June

28-July 1, 1982, pp. F7-F9.

A General Extrapolation Technique which

eliminates the effects of ground reflections In absolute gain measurements Is

described. It utilizes the

Extrapolation Method developed at NBS

which, In its present form, utilizes

only amplitude versus distance data.

However, for broadbeam antennas such as those encountered below 1 GHz, ground

reflections may produce unwanted

oscillations in the amplitude versus distance data. Hence the data are not

amenable to the curve fitting procedure

of the Extrapolation Method. This

problem can be overcome by including

phase versus distance information to

negate the effects of ground

reflections.

Stubenrauch, C. F., Spiess, W. , Galliano, P. G.

,

and Babij, T.

,

International Intercomparison of

Electric Field Strength at 100 MHz,

to be published in IEEE Trans.

Instrumentation and Measurement

[see also paper having same title in

Digest, 1982 Conference on Precision

Electromagnetic Measurements, Boulder,

Colorado, June 28-July 1, 1982, pp. P3-

P4]

.

This paper discusses an international

intercomparison of electric field

strength at IDO MHz. Laboratories in

four countries participated in the

intercomparison. Measurements from each

of the laboratories fell within a range

of +0.75 dB to -0.5 dB with respect to

the overall average. The transfer

standard used in the measurement is

described and the details of the results are presented.

Wyss, J. C., Kanda, M., Melqulst, D. G.

,

and Ondrejka, A. R., Optical

Modulator and Link for Broadband

Antennas, Digest, 1982 Conference on Precision Electromagnetic Measurements,

Boulder, Colorado, June 28-July 1,

1982, pp. P16-P17.

To avoid pick-up and electromagnetic

perturbation problems normally

associated with the use of metallic

cables between an antenna and receiver

electronics, an optical modulator and

optical link are used instead. Laser

light (632.8 nm) is modulated at the

antenna by an electro-optical, lithium

tantalate crystal and is then

transmitted optically to the receiver

electronics where the laser light is

detected using an avalanche phototransistor. The crystal is mounted

directly on the antenna without amplifiers or other active components. In initial tests, a modulating voltage is

applied directly to the antenna. The

frequency response was tested to be flat

(±3 dB) from 10 MHz to at least 430 MHz.

The output signal was linear from 0.01 - 10 V input with a signal to noise ratio

of 2:1 at 10 mV input.

Yaghjian, A. D. , A Delta-Distribution

Derivation of the Electric Field In the

Source Region, Journal of the

Electromagnetic Society, 2, No. 2, pp.

161-167 (April/June 1982).

The sequential approach to distribution

theory is used to rigorously derive the

expression, which remains valid in the source region, for the electric field in

terms of the electric dyadic Green's

function. Sufficient conditions for the

behavior of the current density that

insure that the electric field obeys
CEEE Technical Progress Bulletin Page 7 Antenna Metrology , cont'd.

Maxwell's differential equations are determined explicitly.

Noise Metrology

Wait, D. F., Precision Measurements of

Antenna System Noise Using Radio

Stars, to be published in IEEE Trans,

on Instrumentation and Measurement

[see also paper having same title in

Digest, 1982 Conference on Precision

Electromagnetic Measurements, Boulder,

Colorado, June 28-July 1, 1982, p. F17].

This paper reviews the National Bureau

of Standards (NBS) precision noise

measurements program for antenna systems

which have been made using Cassiopeia A

and the moon. The Earth Terminal

Measurement System (ETMS) was developed

by NBS to make measurements of figure of

merit (G/T), and the noise equivalent

flux (NEF). The accuracy of the noise

measurements are typically between five

and fifteen percent for systems with

antenna gains between 51 and 65 dB and

frequencies between 1 and 10 GHz.

Microwave and Millimeter-Wave Metrology

Hoer, C., On Determining the

Characteristic Impedance of a Coaxial

Transmission Line, to be published in

IEEE Trans. Microwave Theory and

Techniques [approved April 1982].

When a length of transmission line is

used as the standard in calibrating a network analyzer, the loss and phase

shift through the line are usually

determined along with parameters

describing the network analyzer. The

characteristic impedance, ZQ , of the

line can be determined from this loss

and phase shift and the capacitance of

the line. The capacitance can be calculated from the line dimensions or mea- sured at a low frequency such as 1 kHz.

r n example shows how the loss and phase

shift, and hence Z Q , of the line

change with frequency.

Hoer, C., Choosing Line Lengths for

Calibrating Network Analyzers, to be

published (winter 1983-84) in IEEE

Trans. Microwave Theory and Techniques,

[approved April 1982].

Equations, examples, and a table are given to help choose the best length for

a precision transmission line which is

used in calibrating a network analyzer.

One line will cover a frequency range of

about 10:1. Two lines will cover a range of about 65:1.

Laser metrology

Case, W. E., Documentation of the NBS

C, K, and Q Laser Calibration Systems,

NBSIR 82-1676, (September 1982),

This report provides a complete guide

for the documentation of the NBS laser

power and energy calibration systems.

The report also describes a detailed

procedure for operating the three (C, K,

and 0) calibration systems under

computer control.

Optical Fiber Metrology

Danielson, B.L., Franzen, D.L.,

Gallawa, R.L., Kim, E.M., Young, M.

,

Characterization of a Concentric-Core

Fiber, NBSIR 82-1661 (April 1982).

Several optical properties of a concen- tric core fiber are examined. These

include attenuation, radiation patterns,

pulse broadening, index profile, backscatter signatures, signatures, and capture fraction experimental techniques

are briefly described and the signifi- cance of the measured parameters is

di scussed.

Day, G. W. , Danielson, B. L. , Franzen,

D. L. , Kim, E., Young, M.; Editors,

Optical Fiber Characterization, NBS

SP- 637, Vol . 1, (July 1982).

Optical fiber waveguide measurements are described. Systems to determine the

backscatter, bandwidth, and index profile covered in detail. Measurement
Page 8 CEEE Technical Progress Bulletin

Optical Fiber Metrology , cont'd.

comparisons between laboratories are given for fiber attenuation, bandwidth,

numerical aperture, and core diameter.

Gallawa, R. L. , On the Definition of

Fiber Numerical Aperture, Electrooptical Systems Design, p 47, April

1982.

This paper addresses the definition of

the fundamental fiber optics term:

fiber numerical aperture. The popular

definition of the term is not adequate

as a measure of light-gathering ability,

because of leaky rays. Nevertheless, it

is recommended that the term be accepted

because of its utility for most fibers

in use today.

Kim, E. M. , Franzen, D. L. , TwoDimensional Near-Field Contouring of

Optical Fiber Cores, to be published

in Proc. of the Society of PhotoOptical Instrumentation Engineers

[approved August 1982].

A microcomputer controlled system is

described for measuring the two dimensional near-field radiation pattern from

optical fibers. Because radiation

measurements may be made in two dimensions, a novel method has been devised

whereby a constant Intensity contour of

the core is mapped. A modified LeftMost-Looking ( LML ) digital image

encoding algorithm is used to map the

contour of the fiber core. The isointensity map provides information about

the tolerance field, in which all of the

measured iso-intensity points lie, and core noncircularity. Such information

is useful in determining coupling efficiency at splices, connector joints, and

terminal points. This paper will

discuss the measurement apparatus,

accuracy, precision, stability, and

method of analysis of the NBS system.

In addition, results will be presented

on measurements of core diameters, the

length dependence of such measurements,

wavelength dependence of the radiation

patterns, power law fits to the

patterns, calibration apparatus, and

Iso-Intensity contours of telecommunlcations-grade fibers.

Other Fast Signal Topics

Gibson, K. A., and Miller, C. K. S.

,

Bibliography of the NBS Electromagnetic

Fields Division Publications, NBSIR

82-1673 (August 1982).

Covers period from January 1980 through

December 1981.

Roe, K. C., and Wittmann, R. C.,

Improved Coal Interface Detector,

NBSIR 82-1663 (May 1982).

This report describes the theory,

design, construction and testing of an electromagnetic coal interface detector.

The purpose of this type detector is

measuring the thickness of roof coal

left during underground mining

operations. An above ground test

facility constructed to evaluate the

coal interface detector is also

descri bed.

Stoltenberg, R. E., and Wittmann, R. C.,

Acoustical Interferometer Wader

Final Report of Advanced Development

Test and Evaluation, NBSIR 82-1671

(June 1982).

This document reports and evaluates the

results of the Advanced Development Test

and Evaluation of the Advanced Development Model (ADM) of the Acoustic Interferometer Wader (AIW) detector. The

Acoustic Interferometer is a security

device designed to detect penetration of

secure areas by human intruders

traversing shallow water, primarily by

wading. This report describes the

conduct, analysis, conclusions, and

recommendations of the final tests

conducted by NBS to determine the

performance of the ADM. The AIW

detector is an active, low frequency,

totally automatic system. It utilizes

relatively low cost components and can

be deployed and operated with minimal

skills making it suitable for quick
CEEE Technical Progress Bulletin Page 9

Other Fast Signal , cont'd.

response situations. The Advanced

Development, Test, and Evaluation

activity examined the performance with

respect to Probability and Detection,

False Alarm Rate, and Nuisance Alarm

Rate, for the following variables:

environment; wader types, wader paths,

wader attire, insoni fication, and time

of day. The tests were conducted

utilizing a computer-controlled

sophisticated data acquisition and

analysis system. This data acquisition

system permitted a complete record of

not only the system performance but the

precise time record of logic events

which allowed the investigation of an alternate family of performances based

upon the same data base.

Young, M. , Objective Measurement and

Characterization of Scratch Standards, to be published in Proc.

Society of Photo-Optical Instrumentation Engineers [approved July 1982].

The manufacture of scratch standards for

use with MIL-0-13830A has been hampered

by the lack of an objective measurement

technique. The II. S. National Bureau of

Standards has therefore undertaken a comprehensive program to provide quantitative measurements of the light scattered by the scratches and to correlate

them with assessments made by trained

observers. In this paper, I apply

scalar diffraction theory to developing

design criteria for a polar scanning

apparatus, describe the apparatus, and

show scans from one full set of secondary standards. Comparing these scans with the visual assessments is not

straightforward.

ELECTRICAL SYSTEMS

Po wer Systems Metrology

h.bner, R.E., Development of Power

$ stem Measurements — Quarterly Report

January 1, 1982 to March 31 , 1982,

N

B

r T

n

82-8528 (June 1982).

This report documents the progress on four technical investigations sponsored

by the Department of Energy and

performed by the Electrosystems

Division, the National Bureau of

Standards. The work described covers

the period from January 1, 1982 to March

31, 1982. The report emphasizes the

calibration of instruments designed to

measure the 60-Hz electric field in

biological exposure facilities, selected

errors inherent in the use of timedomain reflectometry to determine the rf

characteristics of power cables, the

measurement of the rate of decomposition

of S F 5 in positive dc-corona

discharges, and in the measurement of

space charge in transformer oil between

100°C and 150°C.

Hebner, R.E., Developments of Power

System Measurements — Quarterly Report

October 1, 1981 to December 31, 1981,

NBSIR 82-2501 (May 1982).

This report documents the progress on four technical investigations sponsored

by the Department of Energy and

performed by the Electrosystems

Division, the National Bureau of

Standards. The work described covers the period from October 1, 1981 to

December 31, 1981. The report

emphasizes measurements of ion density

in air, the use of signals above 1 GHz

to detect incipient faults in cables,

the measurement of by-products which

develop during partial discharge

activity in S F 5 s and the

determination of the breakdown behavior

of an oil-paper interface.

Hillhouse, D. L. , Petersons, 0., and

Sze, W. C., A Simplified System for

Calibration of CCVTs In the Substation, NBS Tech. Note 1155 (May 1982).

Coupling capacitor voltage transformers

(CCVTs) are widely used for the revenue metering of energy exchanged between

utilities at EHV (345-500 kV)

interties. These devices are installed

permanently in substations, and must be

calibrated there. Allowable error is
Page 10 CEEE Technical Progress Bulletin

Power Systems Metrology , cont'd.

±0.3% and ±4.6 mrad (mi 1 1 i radi ans) . NBS

developed, and has had in operation for

several years, a prototype system for

field calibration of these CCVTs. This

prototype system is more accurate, more

complicated, more bulky, and more costly

than is essential for this application.

This report describes a simplified,

lighter, and less costly CCVT

calibration system, newly developed and

field tested by NBS. The principal

elements of this system are a portable

reference standard transformer and moderate voltage power supply (14.4 kV), a modular capacitive transfer standard

divider, and a voltage comparator.

Results obtained with this system agree

with the prototype to within ±0.03% and

±0.1 mrad. The prototype system is

installed permanently in a dedicated

calibration truck. The new system could

operate with a non-dedi cated truck to

transport the disassembled modular

divider, and a van to transport the rest

of the components and to serve as a field laboratory.

Kelley, E. F., Hebner, R. E., Forster,

E. 0., and FitzPatrick, G. J. , Observations of Pre- and Post-Breakdown

Events In Polydimethyl si 1 oxanes

,

Proc. 1982 IEEE Int. Symposium on Electrical Insulation, Philadelphia,

PA, June 7-9, 1982, pp. 255-258.

The effect of viscosity and rate of

voltage application on the electrical

breakdown process in four polydimethyl si loxane fluids has been investigated under nonuniform field conditions using a highspeed image converter

camera. The viscosity of these fluids

ranged from ID to 10,000 cSt, and the

rate of rise of the approximately

trapezoidal voltage pulse varied from 10

to 42 kV/us. It was noted that, within

experimental error, viscosity had no effect on the breakdown process. When

the cathode was a point, pre-breakdown

streamer propagation was shown to be

related to the rate of rise of the

applied voltage, and the breakdown

voltage was highest for the highest

rate. When the anode was a point, the

streamer propagation was approximately

independent of applied voltage. The

time to cross the gap of 3mm was determined to 0.6 ± 0.1 ys independent

of the fluid's viscosity. The

implications of those findings are discussed in the light of existing

theories.

Mcknight, R. H. , The Measurement of

Net Space Charge Density Using Air

Filtration Methods, NBSIR 82-2486

(April 1982).

The efficiency of a high efficiency

particulate air (HEPA) of absolute

filter for removing charge from an air

stream has been measured for a variety

of space charge and air flow conditions.

Ion densities ranged from 10 5 to 10 6 /cm 3 and were for positive and negative space

charge as well as mixtures. For all

conditions studied, the transmission of

the filter was less than 0.1%. For

space charge consisting predominantly of

ions of one polarity, space charge density measurements made using HEPA

filters and ion counters may be compared

directly. The filter is well suited for

all accurate measurements of net space

charge density. Three other types of

fibrous filters also have been studied.

McKnight, R.H., and Kotter, F.R., A

Facility to Produce Uniform Space

Charge for Evaluating Ion Measuring

Instruments, to be published in IEEE

Trans. Power Apparatus & Systems [also

available as NBSIR 82-2517 (June

1982)].

A low-speed wind tunnel containing space

charge has been constructed and

evaluated. The facility is used for

testing the performance of ion counters

and net space charge measuring devices.

Depending on location within the system,

space charge densities range from 2.5 to

5.7 x 10- 8 C/m 3

. The space charge

density is spatially uniform within ±5%

over more than 90% of the crosssectional area of the test volume, but
CEEE Technical Progress Bulletin Page 11

Power Systems Metrology , cont'd.

decreases by approximately 20% between

two positions separated by 1 m. Ion

densities achieved in this system are comparable to those found near highvoltage dc transmission lines but are free from the accompanying large

electric fields.

Mcknight, R.H. , Kotter, F.R., Mikasian,

M., and Hagler, J.N., 1981 Annual

Report — Electrical and Magnetic Field

Measurements, NBSIR 82-2527 (July

1982).

The NBS program is concerned with

developing methods for evaluating and

calibrating instrumentation for use in

measuring the electric field and various

ion-related electrical quantities in the

vicinity of high-voltage di rect-current

( HVDC ) transmission lines and in

apparatus designed to simulate the

transmission line environment.

The laboratory investigation of errors associated with above-ground operation

of sensors for measuring vertical

current density has been completed.

Significant errors were observed for

both unguarded and guarded sensors,

ranging from 4 to 25% for the guarded

plates and 10 to 35% for the unguarded

plates for a wide range of geometrical

parameters. Preliminary results from a field day held in October 1981 are in

agreement with the laboratory results.

A new low-speed air-flow facility has

been constructed. Using multiwire

planar corona discharge ion sources, ion

densities from 1.6 x 105 /cm 3 to 1.4 x 106 /cm 3 have been measured using an absolute filter technique.

Losses at the inlet of a parallel plate

ion counter due to fringing fields have

be' n determined using an ion counter

h variable geometry. Calculations

l ed on a two-dimensional finite

element code predict a greater loss than

ect tally observed, but are in

qualitative agreement with experimental

results.

The above-ground operation of a parallel

plate has been investigated using a monopolar line. The initial results

obtained show that the ion densities

measured using the counter are strongly

dependent on ion counter potential.

These results represent only a limited

set of measurements, but indicate

problems associated with above-ground

measurements of ion density.

The transmission of charge in an air

stream through a high-efficiency

particulate air (HEPA) filter has been

determined to be less than 0.1% for a wide range of flow and ion density

conditions. The result indicates that a HEPA filter may be useful in calibrating

ion counters when the net space charge

density and ion density are equivalent.

A retarding field scheme has been

considered for use in measuring the

mobility spectrum of the ions in the

low-speed air flow facility. The

results of a limited number of

measurements show that the method may be

a useful one for this application but

that a number of problems need further

investigation, including the effects of

space charge.

Ramboz, J. D. , Ondrejka, A. R., and

Anderson, W. E. , Sampling-Rate Drift

Problems In Transfer Function Analysis

of Electrical Power Cables, Proc.

Waveform Recorder Seminar, Boulder,

Colorado, October 1981, NBS Spec. Pub.

634, pp. 47-53 (June 1982).

An examination of measurement problems

caused by sampling-rate drift has been

initiated at the National Bureau of

Standards. This work arose from the

study of degradation in underground

power distribution and transmission

cables, where precise measurements of

radio-frequency dispersion characteristics (i.e., attenuation and phase

delay as a function of frequency) are necessary. Cable dispersion results are
Page 12 CEEE Technical Progress Bulletin

Power Systems Metrology , cont'd.

obtained using time-domai n-refl ectometry

and fast Fourier transform methods and

spectra obtained from different data

sets are compared. But because the data

are necessarily taken at different

times, drifts in sampling rate can occur

and cause erroneous results in the

frequency domain. Measurement methods

for the detection of sampling rate

drifts and computation methods for

correcting the data are discussed and

i 1 lustrated.

Van Brunt, R. J. , Effects of H2 O on the Behavior of SF6 Corona, Proc.

Seventh Int. Conference on Gas

Discharges and Their Applications,

London, England, August 31-September 3,

1982, pp. 255-258.

The effects of trace amounts of H 2 O

vapor (<300 ppm) on poi nt-to-pl ane dccorona inceptions and corona pulse

characteristics in SFg were

investigated. Corona discharges were generated in short gaps, 1.0 to 3.0 cm,

for sharp point electrodes of diameter

~0. 1 mm, and for gas pressures in the

range of 100 to 400 kPa. Trace levels

of H 2 O were introduced by electrical

heating of a wire in the gas, and its

concentration was monitored with a gas

chromatograph-mass spectrometer. Water

vapor was found to significantly enhance

the intensity of corona at a given

voltage, as indicated by an order of

magnitude or more increase in average

discharge current and corona pulse rate.

The presence of small quantities of

h 20 greatly inhibits formation of

positive streamer burst pulses and

significantly modifies the shape of the corona pulse height distribution. On

the other hand, introduction of H 2 O

results in only a slight reduction in

the overall dielectric strength of

SF 6 .

Pulse Power Metrology

Kotter, F.R., and Smith, A.N., A Study

of Air-Gap Breakdown at 28.5

kilohertz, to be published in IEEE

Trans. Power Apparatus and Systems.

Measurements of the electrical breakdown

of both quasi -uni form- and highly non- uniform-field air gaps at a frequency of

28.5 kHz are reported. Gap lengths between a variety of electrode geometries

ranged from a few centimeters to over 2 m. Breakdown voltages significantly

below the corresponding 60-Hz values were observed with electrodes for which

appreciable pre-breakdown discharges

occurred. A pattern of "anomalous"

flashovers at considerably lower than

the normal breakdown voltages was noted

with quasi-uniform field gaps. The

results appear to correlate well with

the data found in the literature for

higher frequencies but lower voltages.

McKnight, R.H., and Hebner, R.E.,

Editors, Measurement of Electrical

Quantities In Pulse Power Systems,

Proc. Workshop on Measurement of Electrical Quantities in Pulse Power Systems, NBS Special Pub. 628 (June 1982).

The Workshop on Measurement of Electrical Quantities in Pulse Power Systems

addressed measurements in pulse systems

having the characteristics of pulse

duration less than a millisecond, system

voltages greater than 10 kilovolts, and

system currents greater than 10 kiloamperes. The presented papers were divided into four categories: voltage

measurements, current measurements,

power and energy measurements, and data

acquisition. Included are discussions

of applications of conventional measurement techniques and state-of-the-art

systems.

Magnetic Materials and Measurements

Fickett, F. R., Low Temperature Material Perspective, Advances in Cryogenic Engineering, 28, pp. 1-16, July

1982.

The evolution of materials research at

cryogenic temperatures is traced from

its earliest beginnings to the present
CEEE Technical Progress Bulletin

Magnetic Materials & Meas ., cont'd.

day. The emphasis is on developments in

the United States. Nonsuperconducting

components of cryogenic systems are the

main topic, but practical superconductors are not neglected. An

assessment of the data base as it now exists is presented as well as some projections for the future. A few mildmannered comments are made regarding the

modern tendency to first build large

devices and then do the materials

research.

Zimmerman, J. E., Biomagriietlsm: an Interdisciplinary Approach - Chapter 2;

Magnetic Quantities, Units, Materials,

and Measurements - Chapter 3 of book.

Cryogenics, to be published as NATO

Advanced Study Institute Publication

[approved September 1982].

The intent of the overall work is that

it be intelligible to both physical and

medical scientists. Chapter 2 covers the terminology of magnetism, simple

theory of magnetostatics. Ohm's Law,

electric and magnetic SI units, magnetic

materials, magnetic sensors, and

magnetic measurements. Chapter 3 covers Nyquist noise and construction of dewars

and refrigerators for SQUID

magnetometers.

Superconductors

Clark, A. F., Development of Standards

for Superconductors, NBSIR 82-1678

(July 1982).

A cooperative program with the Department of Energy, the National Bureau of

Standards, and private industry is in

progress to develop standard measurement

practices for use in large scale

applications of superconductivity. The

goal is the adoption of voluntary standards for the critical parameters and

ier characteri zations of practical

perconductors . Progress for the

period October 1980 through January 1982

Is reported. The major effort was the

devil roment of a standard test method

Page 13

for critical current, the necessary

back-up research, and the coordination

of the adoption of the test method and a standard terminology through the subcommittee level in ASTM.

Ekin, J. W., Effect of Strain on the

Critical Parameters of V2 (Hf,Zr)

Laves Phase Composite Superconductors; Appl . Phys. Ltrs., 40(9),

pp. 844-846, May 1982.

Strain effects on the critical parameters of c om p o s i t e - p r o c e s s e

d

Mi (Hf,Zr) Laves phase superconductors

have been examined. The critical temperature is found to be insensitive to

the strain induced by the thermal differential contraction between the com- posite components. Critical current versus uniaxial strain curves obtained

are completely flat at magnetic fields

up to 19 T. It also turns out that the

bulk upper critical field shows essen- tially no sensitivity to uniaxial

strain. These results, which are quite

different from those reported for A15

compound superconductors, are discussed

in terms of the structural insensitivity

of the Laves phase superconductors.

Fractography suggests that the mechanical properties of Mi (Hf,Zr) composite

conductors may be improved by the grain

refinement of component alloys.

Ekin, J. W., Superconductors, to be

published as Chapter 13 in book.

Materials at Low Temperatures

[approved May 1982].

An introduction to practical superconductors is presented. Topics covered

are critical temperature, critical magnetic field, critical current, conductor

fabrication, stability, ac losses, and

mechanical properties. An introduction

to each property is presented along with

typical data on practical materials and

a brief treatment of the experimental

methods used to measure the property.

For quick reference, the chapter con- tains an overall summary and reference

guide to the principal parameters

affecting superconductor material
Page 14 CEEE Technical Progress Bulletin

Superconductors , cont'd.

selection and multifilamentary composite

design.

Ekin, J.W., Fluklger, R. , Specking, W.

,

Effect of Stainless Steel Reinforcement

on the Critical-Current versus strain

Characteristic of Multi-filamentary

NB3Sn Superconductors , to be published in Applied Physics Letters

[approved August 1982].

A series of mul ti fi 1 amentary Nb 3 Sn

superconductors were fabricated containing from 0% to 52 vol.% stainless steel

rei nforcement strands as an integral

part of the conductor. Critical -current

versus strain measurements are reported

which show that the stainless steel

introduces a relatively large compressive prestrain ^ = 0.84% for 52 vol.%

stainless steel. Accompanying this high

compressive prestrain in the reinforced

conductors Is a large degradation of the

conductor's critical current, I c . The

Ic degradation relative to the strainfree value has been measured, for example, to be more than 50% at 13 T for

= 0.64%. Several methods are discussed for reducing the large I c degradation in Al 5 superconductors containing integral reinforcement.

Ekin, J. W, Pittman, E. S., Supercynski,

M. J., and Waltman, D. J. , Training

Studies of Epoxy- Impregnated

Superconductor Windings, Advances in

Cryogenic Engineering, 28, pp. 719-

728, (Plenum Press, NY), July 1982.

A systematic study of training is being

carried out in epoxy-impregnated NbTi

superconductor windings. The effects of

the following factors on training are reported. 1) coating the superconductor

with an epoxy release agent, 2) adding a milled fiberglass filler to the epoxy

impregnant, 3) prestressing the

superconductor prior to winding, 4) room temperature cycling of a trained

winding, and 5) vacuum impregnating

superconductor windings with wax instead

of epoxy. The results indicate that a

major source of training in epoxy

Impregnated magnets Is microfracture of

the epoxy resin.

Goodrich, L. F., Flckett, F. F.,

Critical Current Measurement: A

Compendium of Experimental Effects;

Cryogenics, pp. 225-242, May 1982.

The results of a program to evaluate the

measurement of the critical current of

relatively small ( <6 00A ) practical

superconductors are presented. Experimental data showing the effect of various parameters on the measurement are given. Specific areas covered are:

experimental design and sample mounting;

electric field and resitivity criteria;

field and current; and temperature and

strain effects. The goal of the presentation is to describe the critical current measurement process and its pitfalls in sufficient detail to serve as a guide for those relatively new to the

field of practical superconductors.

Goodrich, L. F., Ekin, J. W. , and

Fickett, F. R., Effect of Twist Pitch

on Short-Sample V-I Characteristics of

Mul ti fi lament ary Superconductors,

Advances in Cryogentic Engineering, 28,

pp. 571-58, (Plenum Press, NY) July

1982.

The voltage tap location on short sam- ples of twisted multifilamentary superconductors can result in anomalous V-I

characteristics and significantly affect

the determination of critical current.

A phenomenological model of the effect

has been developed based on the twist

pitch of the wire and current-transfer

theory. Extensive experimental data has

ruled out other potential explanations

for the observed behavior.

ELECTROMAGNETIC INTERFERENCE

Adams, J. W. , Measurement of Electromagnetic Radiation from Electric Rail

Cars, NBSIR 82-1669 (August 1982).

Existing Electromagnetic Compatibility

(EMC) standards are not directly
Page 15 CEEE Technical Progress Bulletin

ELECTROMAGNETIC INTERFERENCE, cont'd.

applicable for measuring Electromagnetic

Interference (EMI) from an electric-rail

vehicle. This report describes a mea- surement system and procedure that has

potential for making the needed measurements. This system and procedure need

further evaluation, use, and Improvement

before they could be considered for

general use. The problems that were considered are discussed, and those that

need additional work are given. Sample

measured data from a MARTA rail car is

given. The measurements were performed

at the Department of Transportation Test

Center near Pueblo, Colorado.

Crawford, M. L., Evaluation of

Shielded Enclosure for TEMPEST

Measurements Without and With RF

Anecholc Material, Record, TriService TEMPEST Symposium, Lawrence

Livermore Labs., Livermore, CA,

November 16-18, 1982 [approved

September 1982].

This paper gives the results of measurements performed by the National Bureau

of Standards to evaluate the potential

influence of rf absorbing material

installed inside a shielded enclosure on the accuracy of TEMPEST measurements

made using the shielded enclosure. The

facility evaluated was a 3.76-m wide by

6.2-m long by 2.44-m high shielded

enclosure located at Hanscom Air Force

Base, Massachusetts. The paper briefly

discusses the measurement technique

used, describes the test facility and

test configurations, and the spherical

dipole radiators used for generating the

reference standard fields. Tests were performed to evaluate the influence of

(1) placement location of both the

source and receiving antenna inside the

enclosure, (2) separation distance

between source and receiving antenna,

nd (3) height of source above the floor

f the enclosure on the measurement

lesults. Measurements made before and

after installation of the rf absorbing

material indicated a significant

improvement in accuracy (error typically

less than ±10 dB as compared to >30 dB)

at frequencies above 30 MHz where the

absorber is effective.

Driver, L. D. , and Cruz, J. E., Development of the NBS Isotropic MagneticField Meter (MFM-10), 300 kHz to

100 MHz, Proc. IEEE Int. Symp. on EMC, Santa Clara, California, September

8-10, 1982, pp. 460-467.

An isotropic magnetic-field meter is

described which provides accurate near- zone measurements of H-fields over the

range of 0.01 A /m to 250 A /m from

300 kHz to 100 MHz. This instrument's

many advanced features include (1) wide

frequency coverage, (2) large dynamic

range, (3) flat frequency response, (4)

high overload capacity, and (5) the

capability of measuring each of the

three orthogonal H-vectors, as well as their Hermitian magnitude.

FitzGerrell, R. G.

,

Free-Space

Transmission Loss for Anecholc Chamber

Performance Evaluation, IEEE Trans.

Electromagnetic Compatibility EMC-24,

No. 3, 356-358 (August 1982).

Performance of a rectangular, RF, ane- choic chamber is evaluated by measuring

the relative insertion loss versus separation distance between sources of chamber illumination and small dipole or open waveguide antennas on a particular

measurement axis. Measuring data are compared to free-space transmission loss

calculated using finite-range source antenna gains. A lack of fit between

measured insertion loss and calculated

transmission loss is a measure of

reflections from chamber surfaces

assuming the finite-range gain

calculations are exact for the

separation distances considered. This

assumption is made as a result of

excellent agreement between a smooth curve fit to the measured data and the

calculated free-space data.

Kanda, M. , Ries, F. X., Driver, L. D.

,

and Orr, R. D. , Design Considerations

for Broadband Magnetic-Field Sensors,
Page 16

ELECTROMAGNETIC INTERFERENCE, cont'd.

Digest, 1982 Conference on Precision

Electromagnetic Measurements, Boulder,

Colorado, June 28-July 1, 1982, pp.

P11-P13.

Basic design considerations required to

produce broadband magnetic-field sensors

are discussed. Three different configurations are discussed. The advantages

and disadvantages of each configuration

are presented in terms of its

sensitivity and bandwidth. A physical

discussion is given for the operation of

a shielded loop.

Koepke, G. H. , and Ma., M. T. , A New

Method for Determining the Emission

Characteristics of an Unknown Interference Source, Proc. IEEE 1982 Int.

Symposium on Electromagnetic

Compatibility, Santa Clara, California,

September 8-10, 1982, pp. 151-156.

A method for determining radiation characteristics of leakage from electronic

equipment for interference studies is

being developed. The system uses a transverse electromagnetic cell to isolate the equipment under test from the

environment and to provide the coupling

mechanism for power and phase measurements. This method will completely

determine the far-field radiation power

pattern and the total power radiated

based upon an equivalent electric and

magnetic dipole source,model

.

Wilson, P. E. , Chang, D. C., and Ma

,

M. T. , Input Impedance of a Prohe

Antenna Exciting a TEM Cell, NBS

Tech. Note 1054 (April 1982).

The input impedance of a probe antenna

exciting a transverse electromagnetic

(TEM) transmission line cell is formulated by a variational approach. The

formulation also utilizes the results

from a previous work on the field

distribution Inside a TEM cell excited

by a vertical electrical Hertzian

dipole. The final result of impedance

is shown to consist of two distinct

CEEE Technical Progress Bulletin

terms, which are respectively

contributed by the ordinary rectangular

waveguide and the gap perturbation.

Numerical results for both the real and

imaginary parts of the impedance are given. The resistive part is found to

be proportional to the square of the

probe length, and the reactive part

largely capacitive. The analysis presented herein may be used to study the

effect of cables associated with equipment to be tested inside a TEM cell.
NBS-114A iw ev. 2«BC) U.S. OEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET (See instructions)

1. PUBLICATION OR

REPORT NO.

NBSIR 83-2719-2

2. Performing Organ. Report No. Center for Electronic!

& Electrical Eng.

3. Publication Date May 1983

4. TITLE AND SUBTITLE

Center for Electronics and Electrical Engineering Technical Progress Bulletin

Covering Signals and Systems Program, April 1982 - September 1982

5. AUTHOR(S)

Compiler: J. Franklin Mayo-Wells

6. PERFORMING ORGANIZATION (If joint or other than N BS, see instructions)

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234

7. Contract/Grant No.

8 . Type of Report & Period Covered

NBSIR April 1982 - September 1982

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. State, ZIP)

U.S. Department of Commerce

National Bureau of Standards

National Engineering Laboratory

Center for Electronics and Electrical Engineering

10. supplementary notes

All technical information included in this document has been approved for

publication previously.

Document describes a computer program; SF-185, FIPS Software Summary, is attached.

11. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

fci bi io graphy or literature survey , mention it here)

This is the second issue of an abstract bulletin to be issued quarterly by the

Center for Electronics and Electrical Engineering, National Bureau of Standards.

This issue covers the work of the Center’s Signals and Systems Program for the

second half of Federal fiscal year 1982. Abstracts are provided by technical

area for both published papers and papers approved by NBS for publication.

12. KEY WORDS (Si* to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolon s) antennas; electrical engineering; electrical power; electromagnetic interference;

electronics; instrumentation; lasers; magnetics; microwave; optical fibers;

semiconductors; superconductors.

13. VAILABILITY

X l_lnl imited For Official Distribution. Do Not Release to NTIS

O'der From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 .

V Outer From National Technical Information Service (NTIS), Springfield, VA. 22161

14. NO. OF

PRINTED PAGES

19

15. Price

$7.00

USCOMM-OC 8043-P80
CENTER FOR

ELECTRONICS AND ELECTRICAL ENGINEERING

ELECTROSYS1XMS

DIVISION

I Applied Electrical

I Measurements

Electronic Instrumentation and Metrology

I

ELECTROMAGNfnC FELDS

DIVISION

ELECTROMAGNETIC TECHNOLOGY

DIVISION

SEMICONDUCTOR

MATERIALS AND

PROCESSES

H

H

Antenna Systems

Metrology

Fields Characterization

Interference

Characterization

-I Microwave Metrology

H

OPMe

tical Electronic Metrology

H

Process

Metrology

-H Defect Metrology

JCryoelectronics

I Metrology H

Dimensional Metrology

Superconductors

and Magnetic

Materials

KEY CONTACTS:

Center (720)

Director Mr. Judson C. French

Acting Deputy Director Dr. Donald B. Sullivan

Administrative Officer Ms. Carol P. Mullis

Electrosystems Division (722)

Chief Dr. Oskars Petersons

Electromagnetic Fields Division (723)

Chief Mr. Charles K. S. Miller

Electromagnetic Technology Division (724)

Chief Dr. Robert A. Kamper

Semiconductor Materials and Processes Division (725)

Chief Mr. Robert I. Scace

Semiconductor Devices and Circuits Division (726)

Chief Dr. Kenneth F. Galloway

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(301)921-3541

INFORMATION:

For additional information on the Center for Electronics and Electrical

Engineering, write to or call:

Center for Electronics and Electrical Engineering

National Bureau of Standards

Metrology Building, Room B-358

Washington, DC 20234 Telephone (301)921-3357

USCOMM-NBS-DC